John, Paul, and George are standing in a strawberry field. Paul is 16.0 m due west of John. George is 40.0 m from Paul, in a direction 38.0 degrees south of east from Paul's location.

How far is George from John?

What is the direction of George's location from that of John?

I think it's suppose to be a right triangle but for some reason mine keeps being an obtuse type triangle?

September 29th 2012, 10:31 AM

johnsomeone

Re: Vectors :)

I know there's some nerdy LSD joke about non-euclidean geometry to made here - somehow...

And a joke about how Ringo gets no respect! (Listening to She Said, She Said at the moment - Ringo is great!)

Anyway - yeah, it's an obtuse triangle.

Put them in a plane, with Paul at the origin and John on the positive x-axis. George will be in the 4th quadrant. Use trigonometry to figure out the x and y cooridnate for George. Hopefuly after that you'll know how to answer this problem.

September 29th 2012, 11:03 AM

HallsofIvy

Re: Vectors :)

No, there is no right triangle here. If you draw the lines connecting John, Paul, and George (yes, Ringo gets no respect! But I suspect we are showing our age.) you get a right triangle. You know that the two of the sides of that triangle are 16 and 50 m long and the angle between them is 38 degrees. The "cosine law" (NOT the definition of cosine) is exactly what you need.

September 29th 2012, 12:37 PM

Oldspice1212

Re: Vectors :)

So I just need one right triangle right?

September 29th 2012, 02:52 PM

johnsomeone

Re: Vectors :)

Quote:

Originally Posted by Oldspice1212

So I just need one right triangle right?

Yes, the one for George: "40.0 m from Paul, in a direction 38.0 degrees south of east from Paul's location."
Since Paul is at the origin, this is a line segment of length 40m that's headed 38 degree clockwise, under the x-axis (4th quadrant, x>0, y<0).
From that, you can figure the coordinates of George. And from that, hopefully the rest of the problem will be clear.